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Farming without soil

Many words related to agriculture in English go back to Latin, the language of the Romans. Examples are ager, terra, humus. Agriculture is related to ager (the field) and to terra or humus (the soil). So soilless agriculture seems an odd way to talk about farming. Yet, there is much talk about it today, along with controlled-

First, the history. When 18th century royalty in Europe wanted to eat fruit in the northern climates, they built enclosed spaces to protect orange and banana trees. They called them orangeries. In the U.S., we largely ignored them and got our winter vegetables shipped in from the South.

Greenhouse development continued elsewhere. In Europe and the Far East, it was necessary due to the limited land base. The technology moved from high tunnel plastic hoops ($5 a square foot) to advanced greenhouses ($10 to $20 a square foot) to full CEA ($40 or more).

While growing corn and soybeans in greenhouses is not competitive with growing them where light, heat, and water are less expensive, the new technology is important to all farmers. Gene Giacomelli, director of the Controlled Environment Agriculture Center at the University of Arizona, says many breakthroughs in open-field precision agriculture started in CEA systems. Fertigation and sensors that track plant growth are good examples.

“Sensors and data processing will continue to be the drivers of future generations of CEA,” he says, “as will better lighting systems, better use of inputs, and automation of most operations.”

Still learning

Giacomelli and other researchers are learning that, in the matter of artificial light, it’s about the right color at the right time during daily and seasonal plant cycles. The newer LED sources improve the quality of light and the intensity. “The efficiency of LED lights has doubled in the last two years,” he says, “and we can expect similar gains in the near future.”

Another area of research will get us back to nature. When we fully control the environment and the inputs, we unknowingly might be affecting natural allies like microorganisms. “Plant leaves and roots are colonized by very large quantities of beneficial organisms,” says Giacomelli. “Just like we learned the benefits of probiotics on our body, we are discovering the positive impact of organisms like bacteria and fungi.”

Business decision

In the business of farming, the time is near that decision options will include more acres, or a new combine, or a new greenhouse. From a business viewpoint, is there a difference between building capital intensive grain bins to supply the local ethanol plant or building an advanced greenhouse to supply the local supermarket?

Open-air agriculture and CEA can – and do – coexist. Produce is grown in open fields where and when conditions are best suited. Size matters in this business model. Food is grown from advanced CEA systems in local environments, tailored to specific culinary needs and markets. In this new model, size is no longer the primary discriminating factor.

The remaining question is how soon will this technology become commonplace?